Description
In the Linux kernel, the following vulnerability has been resolved:
KVM: Don't WARN if memory is dirtied without a vCPU when the VM is dying
When marking a page dirty, complain about not having a running/loaded vCPU
if and only if the VM is still alive, i.e. its refcount is non-zero. This
will allow fixing a memory leak for x86 SEV-ES guests without hitting what
is effectively a false positive on the WARN.
For some SEV-ES VM-Exits, KVM keeps a writable mapping of a guest page
across an exit to userspace, and typically unmaps the page on the next
KVM_RUN. But if userspace never calls KVM_RUN after such an exit, then KVM
needs to unmap the page when the vCPU is destroyed, which in turn triggers
the WARN about not having a running vCPU.
Alternatively, SEV-ES could temporarily load the vCPU to suppress the WARN,
as is done in nested_vmx_free_vcpu() (but for completely unrelated reasons;
suppressing WARN from nested_put_vmcs12_pages() is pure happenstance). But
loading a vCPU during destruction is gross (ideally nVMX code would be
cleaned up), risks complicating the SEV-ES code (KVM would need to ensure
the temporarily load()+put() only runs when the vCPU isn't already loaded),
and is ultimately pointless.
The motivation for the WARN is to guard against KVM dirtying guest memory
without pushing the corresponding GFN to the active vCPU's dirty ring, e.g.
to ensure userspace doesn't miss a dirty page. But for the VM's refcount
to reach zero, there can't be _any_ userspace mappings to the dirty ring,
as mapping the dirty ring requires doing mmap() on the vCPU FD. I.e. if
userspace had a valid mapping for the dirty ring, then the vCPU file and
thus the owning VM would still be alive. And so since userspace can't
possibly reach the dirty ring, whether or not KVM technically "misses" a
push to the dirty ring is irrelevant.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.17 | 6.1.191 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 7.0.13-1 | — |
| Debian 13 | linux | 6.12.94-1 | — |
| Debian 12 | linux | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1032.37 | — |
| Ubuntu 26.04 LTS | linux | 7.0.0-31.31 | USN-8726-1 |
| Ubuntu 26.04 LTS | linux-aws | 7.0.0-1012.12 | USN-8726-1 |
| Ubuntu 26.04 LTS | linux-azure | 7.0.0-1014.14 | USN-8726-4 |
| Ubuntu 26.04 LTS | linux-gcp +1 | 7.0.0-1011.11 | USN-8726-4, USN-8726-1 |
| Ubuntu 26.04 LTS | linux-gke | 7.0.0-1006.7 | USN-8726-1 |
| Ubuntu 26.04 LTS | linux-ibm +2 | 7.0.0-1013.13 | USN-8727-1, USN-8726-3 |
| Ubuntu 26.04 LTS | linux-nvidia | 7.0.0-1018.18 | USN-8760-2 |
| Ubuntu 26.04 LTS | linux-nvidia-bos | 7.0.0-2018.18 | USN-8800-1 |
| Ubuntu 26.04 LTS | linux-raspi | 7.0.0-1019.19 | USN-8726-2 |
| Ubuntu 26.04 LTS | linux-riscv +1 | 7.0.0-31.31.1 | USN-8726-1 |
| Ubuntu 25.10 | linux +8 | No fix yet | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-146.146 | USN-8903-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1066.69 | USN-8903-1 |
| Ubuntu 24.04 LTS | linux-aws-7.0 | 7.0.0-1012.12~24.04.1 | USN-8726-1 |
| Ubuntu 24.04 LTS | linux-azure-7.0 | 7.0.0-1014.14~24.04.1 | USN-8728-2 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1068.75 | USN-8904-1 |
| Ubuntu 24.04 LTS | linux-azure-fde-7.0 | 7.0.0-1013.13~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-gcp +1 | 6.8.0-1070.78 | USN-8905-2, USN-8904-1 |
| Ubuntu 24.04 LTS | linux-gcp-7.0 +1 | 7.0.0-1011.11~24.04.1 | USN-8728-3, USN-8728-1 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1065.73 | USN-8903-2 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1051.55 | USN-8903-2 |
| Ubuntu 24.04 LTS | linux-hwe-7.0 | 7.0.0-31.31~24.04.1 | USN-8726-1 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1066.67 | USN-8903-2 |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-146.146.1 | USN-8903-2 |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1064.67 | USN-8903-2 |
| Ubuntu 24.04 LTS | linux-nvidia-7.0 | 7.0.0-1018.18~24.04.1 | USN-8760-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1064.67.1 | USN-8903-2 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1038.42 | USN-9002-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1063.66 | USN-8903-2 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1068.72 | USN-9025-1 |
| Ubuntu 24.04 LTS | linux-riscv +29 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-riscv-7.0 | 7.0.0-31.31.1~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-vmware | 6.8.0-1008.8 | — |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1066.69~22.04.1 | USN-8903-1 |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1068.75~22.04.1 | USN-8904-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 +1 | 6.8.0-1070.78~22.04.1 | USN-8905-1, USN-8904-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 | 6.8.0-149.149~22.04.1 | USN-9066-1 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1066.67~22.04.1 | USN-8906-1 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-146.146.1~22.04.1 | USN-8903-2 |
| Ubuntu 22.04 LTS | linux-nvidia-6.8 | 6.8.0-1064.67~22.04.1 | USN-8903-2 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1067.71~22.04.1 | USN-9025-1 |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv-6.8 | 6.8.0-146.146~22.04.1 | — |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-raspi-realtime | 6.8.0-2056.58 | USN-9025-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1061.62 | USN-8903-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1061.62~22.04.1 | USN-8903-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1066.69+fips1 | USN-8903-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1069.77+fips1 | USN-8904-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-146.146+fips1 | USN-8903-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1070.78+fips1 | USN-8905-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +7 | 6.4.0-150700.53.78.1 | SUSE-SU-2026:3790-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.78.1.150700.17.43.2 | SUSE-SU-2026:3790-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.37.1 | SUSE-SU-2026:23231-1, SUSE-SU-2026:23221-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.37.1.160000.2.19 | SUSE-SU-2026:23231-1, SUSE-SU-2026:23221-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.37.1 | SUSE-SU-2026:23237-1, SUSE-SU-2026:23231-1, SUSE-SU-2026:23221-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.37.1.160000.2.19 | SUSE-SU-2026:23231-1, SUSE-SU-2026:23221-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.37.1.160000.2.19 | SUSE-SU-2026:23068-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.37.1 | SUSE-SU-2026:23068-1, SUSE-SU-2026:23066-1 |
| SLE Micro 6.1 | kernel-rt +4 | 6.4.0-51.1 | SUSE-SU-2026:23194-1, SUSE-SU-2026:23193-1 |
| SLE Micro 6.0 | kernel-rt +4 | 6.4.0-51.1 | SUSE-SU-2026:23244-1, SUSE-SU-2026:23241-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.78.1 | SUSE-SU-2026:3790-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_19 | 1-150700.1.5.1 | SUSE-SU-2026:3810-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_20 | 1-150700.15.3.2 | SUSE-SU-2026:3790-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.72.1 | SUSE-SU-2026:3810-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.37.1.160000.2.19 | openSUSE-SU-2026:21555-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.37.1 | openSUSE-SU-2026:21555-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.18.36-69.134 +1 | 1:1.0-0.amzn2023 | ALAS2023-2026-1968, ALAS2023-2026-1925 |
| Amazon Linux 2023 | perf6.12 +11 | 1:6.12.94-123.174.amzn2023 | ALAS2023-2026-1968 |
| Amazon Linux 2023 | perf6.18 +12 | 1:6.18.36-69.134.amzn2023 | ALAS2023-2026-1925 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.143.1-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-206.104.3.3.el10uek | ELSA-2026-500248 |
Advisories 36
- USN-9066-1 linux-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-9025-1 linux-oracle-6.8, linux-raspi, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8726-1 linux, linux-aws, linux-aws-7.0, linux-gcp, linux-gke, linux-hwe-7.0, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8726-4 linux-azure, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8728-1 linux-gcp-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8728-2 linux-azure-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-9002-1 linux-nvidia-tegra vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8760-1 linux-nvidia-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8800-1 linux-nvidia-bos vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8728-3 linux-oracle-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8760-2 linux-nvidia vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8726-3 linux-ibm vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8727-1 linux-oem-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8726-2 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- WID-SEC-2026-2175 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 10, 2026
- USN-8903-2 linux-gke, linux-gkeop, linux-ibm, linux-lowlatency, linux-lowlatency-hwe-6.8, linux-nvidia, linux-nvidia-6.8, linux-nvidia-lowlatency, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8903-1 linux, linux-aws, linux-aws-6.8, linux-aws-fips, linux-fips, linux-realtime, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8904-1 linux-azure, linux-azure-6.8, linux-azure-fde, linux-azure-fde-6.8, linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8905-2 linux-gcp vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8905-1 linux-gcp-6.8, linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8906-1 linux-ibm-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- ELSA-2026-500248 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Sep 4, 2026
- SUSE-SU-2026:3810-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 31, 2026
- SUSE-SU-2026:23244-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23231-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23237-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23241-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23221-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:3790-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23193-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 26, 2026
- SUSE-SU-2026:23194-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 26, 2026
- SUSE-SU-2026:23066-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 15, 2026
- SUSE-SU-2026:23068-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 15, 2026
- openSUSE-SU-2026:21555-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 12, 2026
- ALAS2023-2026-1968 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 12, 2026
- ALAS2023-2026-1925 Important: kernel6.18 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jul 29, 2026
References
- https://git.kernel.org/stable/c/21b880f040bd0e8b50ff30c5a40db7bf3384ff48
- https://git.kernel.org/stable/c/033d39e41fc30f484f4e4f37fb4cd76b12cbb18e
- https://git.kernel.org/stable/c/66a8e7ddd901023c89a2733494d827eca3f9c1b0
- https://git.kernel.org/stable/c/343e95c8ecc40e0738975ef4ee24c0c35e800e6b
- https://git.kernel.org/stable/c/99d7d43784ae3235026581e9bf892c036e04c8e6
- https://git.kernel.org/stable/c/8618004d3e897c0f1b71d9a9ab860461289bb89a